Fig. 2.

An example of automatic bone metastasis segmentation on MRI images by YOLOv5; the green box was outlined by a nuclear medicine physician, and the red box was the segmented lesion as predicted by the algorithm. The upper right zoomed area in (a): the predicted lesion matched the actual outline; The lower right zoomed corner in (a) and the zoomed box in Fig. 2(b): the algorithm falsely segmented those lesions as metastatic.